INCOME TAXES - Narrative (Details) - USD ($)	Jan. 01, 2017	Jan. 03, 2016	Dec. 28, 2014	Dec. 29, 2013
Operating Loss Carryforwards [Line Items]
Undistributed earnings for certain foreign subsidiaries	$ 500,000
Unrecognized tax benefits	2,014,000	$ 696,000	$ 516,000	$ 79,000
Accrued interest and penalties related to uncertain tax positions	0	$ 17,000
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	148,700,000
Federal | Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Research credit carryforward	4,000,000
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	57,400,000
State | Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Research credit carryforward	$ 4,100,000